摘要目的 探讨扩散峰度成像(DKI)评价肾透明细胞癌恶性程度的价值.方法 回顾性分析经手术病理证实且术前行肾脏DKI检查的67例肾透明细胞癌患者的影像资料.患者行肾脏DWI和DKI检查.对手术病理标本进行Fuhrman病理分级,其中Ⅰ级16例、Ⅱ级17例、Ⅲ级15例、Ⅳ级19例,再分为低级别组(Ⅰ级+Ⅱ级)和高级别组(Ⅲ级+Ⅳ级).测量肿瘤ADC值和DKI成像参数,包括平均扩散系数(MD)、各向异性分数(FA)、平均峰度(MK)、径向峰度(RK)以及轴向峰度(KA).采用单因素方差分析比较不同病理分级患者间MRI参数的差异,采用Pearson相关分析评价MRI参数和病理分级的相关性.结果 肾透明细胞癌不同病理分级患者的ADC、MD、MK、KA和RK值差异有统计学意义(P均<0.05),FA值差异无统计学意义(P>0.05).ADC、MD值与病理分级呈负相关,r值分别为-0.732、-0.799,P均<0.05;MK、KA及RK值与病理分级呈正相关,r值分别为0.699、0.773、0.768,P均<0.05.MD、MK、KA及RK值鉴别低、高级肾透明细胞癌的ROC下面积分别为0.923、0.926、0.892和0.833.结论 DKI成像有助于术前评价肾透明细胞癌的病理分级.

abstractsObjective To investigate the value of diffusion kurtosis imaging (DKI) in assessing grades of clear cell renal cell carcinoma (CRCC). Methods Sixty seven patients with pathologically proven CRCC, who underwent MRI scan preoperatively, were analyzed retrospectively and were divided into four groups according to their pathological grading of cancer, including 16 withⅠgrade, 17 withⅡgrade, 15 withⅢgrade and 19 withⅣgrade. These tumors were then divided into low (Ⅰ+Ⅱ, 33 cases) and high grade (Ⅲ+Ⅳ, 34 cases) groups. ADC, mean diffusivity (MD), fractional anisotropy (FA), mean kurtosis (MK), kurtosis anisotropy (KA) and radial kurtosis (RK) were obtained. Parameters of DWI (ADC, MD, FA, MK, KA and RK) were measured. One-way ANOVA analysis of variance and Pearson correlation were used. Results ADC values of the four groups were (0.87±0.18) ×10-3, (0.76±0.12) ×10-3, (0.63±0.16) ×10-3, (0.43±0.08) ×10-3mm2/s (P<0.05). MD values were 2.68±0.23, 1.94±0.25, 1.72±0.37, 0.67±0.22 (P<0.05). FA values were 0.17 ± 0.03, 0.13 ± 0.04, 0.17 ± 0.06, 0.15 ± 0.05 (P>0.05). MK values were 0.42 ± 0.03, 0.55 ± 0.06, 0.58 ± 0.14, 1.19 ± 0.11 (P<0.05). KA values were 0.44 ± 0.05, 0.60 ± 0.07, 0.61 ± 0.10, 1.53 ± 0.23 (P<0.05). RK values were 0.37±0.08, 0.49±0.09, 0.56±0.16, 0.99±0.19 (P<0.05).Both ADC and MD correlated negatively with tumor grading (r=-0.732 and -0.799, P<0.05). MK, KA and RK values correlated positively with tumor grading (r=0.699, 0.773, 0.768, P<0.05). Areas of MD, MK, KA and RK values under ROC curves to diagnose low and high grade cancers were 0.923, 0.926, 0.892 and 0.833. Conclusion DKI model of multi-b value DWI may provide useful information in the grading of CRCCs preoperatively.